1. Field of the Invention
This invention relates to the use of a topical cream, gel, or other vehicle which contains substances such as L-arginine which delivers these substances into tissue for the purpose of producing beneficial effects such as relief of pain, as well as beneficial effects through a variety of mechanisms such as providing increased levels of natural analgesic kyotorphin and/or restoration of natural mechanisms based on improvement of local blood supply.
2. Prior Art
Approaches to overcoming pain are multiple and consist of oral analgesic agents ranging from aspirin and ibuprophen to more powerful narcotic oral agents such as codeine. Alternatively, in severe pain i.v. administration of agents including such agents as narcotics including morphine are used. Topical agents such as liniments and most recently the agent capsaicin derived from hot peppers have been used with success.
It has been found that the amino acid L-arginine is a precursor to the natural endogenous analgesic substance, kyotorphin. It has been shown that intravenous administration of large amounts (30 g/patient) of L-arginine is successful in overcoming pain. See A. Harima et al. Europ Neuropsych 1, 529 (1991). It is thought that this treatment exerts it effect by increasing levels of kyotorphin. However, this treatment is impractical for use in everyday life and is reserved only for the most extreme forms of chronic pain. Others have found that nitric oxide, whose biochemical precursor is L-arginine potentiates b-endorphin-induced pain relief. See L. Tseng et al. Eur J Pharm 212, 301 (1992). Still other mechanisms of pain relief from administration of L-arginine may exist.
Pain relief comes from a variety of mechanisms. One which is distinct from those by which L-arginine operates is the depletion of substance P from sensory type C fibers. This has been shown to be effected by application of capsaicin, a substance derived from hot peppers. See B. Mathias et al. Am J Phys Med & Rehab 74, 39 (1995).
It was discovered that topical application of the nitric oxide precursor, L-arginine, in its various forms including a variety of topical preparations, either by themselves or with other agents to aid in penetration such as a high ionic strength environment, neutralization of its charge in a complex or by other means, or included in a liposome or other biological carrier, when administered to painful areas of the body can overcome pain in many persons. It was further discovered that such topical preparations described above when fortified with capsaicin or its source extract, oleoresin capsicum, are administered to painful areas of the body can overcome pain in many persons.
In accordance with this invention, a penetrating cream containing L-arginine in a concentration sufficient to produce the desired effect along with sodium chloride or other salts at a concentration sufficient to produce a hostile biophysical environment when applied locally as the cream directly to the painful area was effective in overcoming pain. Further, in accordance with this invention, a penetrating cream containing L-arginine and capsaicin or oleoresin capsicum in concentrations sufficient to produce the desired effect along with sodium chloride or other salts at a concentration sufficient to produce a hostile biophysical environment when applied locally as the cream directly to the painful area was effective in overcoming pain.
Consequently, with the discovery of the present invention, a means to overcome pain has been found.
These and other objects and features of the present invention will become apparent to those skilled in the art from reading the description of the invention, which follows.